Seroprevalence of Mycoplasma Gallisepticum in Do- Mestic Chickens, East Shewa, Ethiopia
Total Page:16
File Type:pdf, Size:1020Kb
Jibril et al., Ethiop. Vet. J., 2018, 22 (1), 74-86 DOI https://dx.doi.org/10.4314/evj.v22i1.6 Ethiopian Veterinary Journal Seroprevalence of Mycoplasma gallisepticum in do- mestic chickens, East Shewa, Ethiopia Yasmin Jibril1*, Yilkal Asfaw1, Berhe Gebregziabher2 and Ahmed Issa3 1Department of Clinical Studies, College of Veterinary Medicine , Addis Ababa University, P.O. Box 34, Bishoftu, Ethiopia. 2 Food and Agricultural Organization (FAO),Rome, Italy 3Prima International Company, Djibouti Regional Quarantine, Djibouti * Corresponding authore mail: [email protected] Abstract Cross sectional study was conducted to estimate the sero-prevalence of Myco- plasma gallisepticumin domestic chickens and to assess risk factors associated with the disease in commercial and local chickens in East Shewa, Ethiopia. A total of 514 sera were collected (from187 commercial chickens and 327 local chickens) and tested using an indirect enzyme linked immunosorbant assay (ELISA) to detect antibodies against M. gallisepticum. The overall seropreva- lence of M. gallisepticum was 49.4% (254/514). A statistically significant asso- ciation (p<0.05) was observed in prevalence between chicken type with preva- lence of 64.5% in local and 23% in commercial chickens. Variation in prevalence was observed among the three commercial farms, the highest being in farm-B (46.8%) and the lowest in farm-C (4.25%). Prevalence in local chickens was sig- nificantly highest in Lume (72.7%) and lowest in Ada’a (47.5%) p<0.05( ). Age was significantly associated with sero-prevalence (p<0.05). Prevalence was 67.3% in layers of (18 to 76 weeks) and 0% in layer chicks of (1 to 8 weeks old). Prevalence was also significantly different between layers (41.7%) and broilers (7.8%) (p<0.05). In commercial chickens, prevalence was significantly higher in females (32.4%) than males (10.1%) (p<0.05). The current study revealed M. gallisepticum is prevalent in chicken in East Shewa, Ethiopia. Keywords: Domestic chickens; East Shewa; Ethiopia; Mycoplasma gallisepti- cum; Sero-prevalence Ethiop. Vet. J., 2018, 22 (1), 74-86 74 Jibril et al., Introduction Agricultural production dominates the Ethiopian economy and contributes to 45% of gross domestic product (GDP) and provides more than 80% of employ- ment. Ethiopia has the highest livestock populations in Africa and accounts for 17% of cattle, 20% of sheep, 13% of goats and 55% of equines in sub-Saharan Africa. Livestock contributes 16% of GDP. Seventy per cent of cattle, 75% of sheep, 27% of goats and 80% of equines are found in the highlands (Tangkaet al., 2002). Of domestic animals in the country, the most numerous are bovines and poultry each estimated 45 million head. This is followed by goats and sheep each at 17 million head, by donkeys (4 million) and by horses and camels (each one million). Poultry are represented exclusively by chickens (FAO, 2008). In developing countries, poultry production offers an opportunity to feed the fast growing human population and to provide income to the resource poor farmers (Gari, 2004). The sub-sector is concerned with egg and meat produc- tion for income generation and home consumption (EARO, 2000; Moham- med, 1998). The main purposes of egg production are hatching (51.8%), sales (22.6%), home consumption (20.2%) and gift (5.4%). The purposes of bird pro- duction are sales (26.6%), sacrifice/healing ceremonies (25.0%), replacements (20.3%), home consumption (19.5%) and gift (8.6%) according to Gottard and SoaresMagalhaes (2006). In Ethiopia, live birds and eggs are usually sold by the owner in local markets. Single bird sales or sales of small numbers typify most rural markets, with many sellers competing. During times of festivity, the numbers and the prices of birds in the market rise considerably, because of demand (Dessie and Ogle, 2001). Occasionally, birds are sold to middlemen for transport and sales in the larger towns and cities. The largest proportion of eggs and poultry meat con- sumed in the country comes from indigenous birds produced by rural growers. Large numbers of these birds are also exported to neighboring countries within trade that is mainly informal. Therefore, the main movement of poultry and poultry products is one of rural producer to urban consumer and from Ethiopia to neighboring countries, which from an Ethiopian biosecurity point of view is profitable, because it is not favorable to the diffusion of poultry diseases all over the country (FAO, 2008). Mycoplasma gallisepticum (MG), the etiologic agent of chronic respiratory dis- ease (CRD), is one of the major pathogens of domestic poultry causing signifi- 75 Ethiop. Vet. J., 2018, 22 (1), 74-86 Jibril et al., cant economic losses particularly to the commercial poultry industry resulting in reduced feed conversion, reduced egg production and significant downgrad- ing of carcasses at slaughter. The disease has a worldwide distribution and is extremely important to both the broiler grower and the table egg producers. Infection of air sacs in broilers (air sacculitis) is the cause for condemnation of dressed birds as unsuitable for human consumption. Laying flocks positive for MG have been shown to produce as many as 20 fewer eggs per year than MG negative flocks (Garciaet al., 2001; Talha, 2003). With the huge population of chickens being reared and the industry steadily growing, major disease problems of commercial and local chickens have not been well investigated in Ethiopia. There is no documented work on the sta- tus and distribution of MG infection in Ethiopia. The objectives of this study, therefore, were to estimate the sero-prevalence of M. gallisepticum in com- mercial and local chicken production systems in East Shewa, Ethiopia, and to assess risk factors for the sero-prevalence. Materials and methods Study area The study area, East Shewais located in the center of Ethiopia with area of 14,050.27km2. Ithas an altitude range of 3100 to less than 1000 meter above sea level (masl). It is located in the middle of Oromia, connecting the western regions to the eastern ones. This zone is bordered on the south by the West Arsi Zone, on the southwest by the Southern Nations, Nationalities and Peoples Re- gion, on the west by South west Shewa and Oromia Special Zone Surrounding Addis Ababa, on the northwest by North Shewa, on the north by the Amhara Region, on the northeast by the Afar Region, and on the southeast by Arsi; its westernmost reach is defined by the course of the Bilate River. Towns and cities in East Shewa include Bishoftu (DebreZeit), Metehara, and Ziway. The town of Adama was separated from East Shewa and is a special zone now. Five woredas were randomly selected: Ada’a, Boset, Gimbichu, Lume, and Adami Tulu. Gimbichu lies in the highland with about 2450 masl,Ada’a and Lume fall under mid-high land of 1600-2300 masl, whereas Boset and Adamitulufall un- der low land with an altitude range of 1200-1500 masl (https://wikipedia.org/ wiki/EastShewaZone, Web retrieved May, 2018). Ethiop. Vet. J., 2018, 22 (1), 74-86 76 Jibril et al., Study animals A total of 514 chickens sera were collected (187 from commercial and 327 from local chickens). For local chicken production, chickens were randomly bought from market places of the selected five Woredas, whereas, commercial chickens (layers and broilers) were obtained from the three selected commercial poultry farms in Bishoftu, East shewa, Ethiopia, which were coded, for confidential- ity, as farm-A, farm-B and farm-C. The farms undertake regular vaccination against New Castle Disease (NCD), Gumboro (IBD), fowl typhoid, fowl pox, and Infectious Bronchitis (IB). The housing was deep litter system for broilers and layer chicks: whereas, battery cage system for layers. Feeding and watering system was through automatic feeders and waterer. Birds were supplemented with minerals, amino acids, and vitamins produced locally and imported. The layer breeds were of Bovan-Brown, Rod Island Red (RIR), and Lohmann; and broiler breeds were of Cobb-500 and Rose. Layer and broiler flocks of different age were included (Table 1). Table 1. Study chickens with different age group, sex, and number of samples taken Age group and bird type Production system Commercial Local chickens chickens Broiler Grower (3 to 6 weeks) 61 - Finisher (6 to 10 weeks) 42 - Layer Chicks (1 to 8 weeks) 32 - Layers (18 to 76 weeks) 52 - Local Adult local - 327 Sex Male 79 145 Female 108 182 Total 187 327 In farm-A, both layers and broilers with one flock of layer chicks and one flock of commercial layers, and two flocks of broiler growers and two flocks of broiler finishers were considered; in farm-B, layer flocks with one flock of layer chicks and one flock of commercial layers; and in farm-C, broiler flocks with one flock of broiler finisher and two flocks of broiler growers were considered for the 77 Ethiop. Vet. J., 2018, 22 (1), 74-86 Jibril et al., study (Table 2). None of the commercial chickens were vaccinated against MG infection. Table 2. Number of commercial chickens (layers and broilers) sampled Commercial chickens Farm-A Farm-B Farm-C Total Layers Chicks 19 13 - 32 Layers 18 34 - 52 Broilers Grower 40 - 21 61 Finisher 16 - 26 42 Total 93 47 47 187 Study design and sample size determination Cross sectional study with stratified random sampling was followed. Poultry production system was stratified into commercial and local chicken produc- tion systems. In commercial, layer flock chicks (1 to 8 weeks old) and layers (18 to 76 weeks), and broiler flocks with broiler grower (3 to 6 weeks) and fin- isher flock (6 to 10 weeks) were included for the study. Chickens of both sexes and different age groups were stratified and sampled randomly.